Nice concept map to help revise this section:
The six major nutrients (you also need fibre):
Science Bank 21 (Food & Digestion): part 1 – Food Tests; part 2 – the Digestive System (from 4m 40s); part 3- Digestive Enzymes (from 9m):
Bitesize Top 20 Demos – Food as a Fuel (2m 16s).
Here’s a useful powerpoint, although it doesn’t cover everything we need to know:
The use of microorganisms in the manufacture of yoghurt, notes here and video here:
IGCSE Biology: Coursebook, chapter 4, pp.31 – 37 & chapter 7, pp.64 – 66 & 69